Steering columns generally comprise a shaft, one end of which is secured to a steering wheel that drives it and is turned by the driver of the vehicle and the other end of which is secured to mechanical members the role of which is to perform the angular positioning of the wheels of the vehicle. The steering column shaft is mounted such that it can rotate in a tubular housing via two rolling bearing devices each comprising a rolling bearing, generally an angular-contact ball bearing, which are mounted in opposition.
The rolling bearing generally comprises an inner ring and an outer ring, each ring being provided with a raceway and a row of rolling elements arranged between the two raceways of the rings. The rolling bearing is mounted in the housing via its outer ring and on the shaft via a sleeve or a ring known as a tolerance ring which makes it possible to compensate for any geometric defects there might be between these two components. The tolerance ring allows the rolling bearing to be mounted easily on the shaft without any initial clamping.
The assembly preferably operates with zero play thanks to an axial preload applied to the sleeve by an axially elastic member. The internal clearances of the rolling bearing are thus taken up and permanent contact between the rings and the rolling elements of the bearing is ensured.
WO 01/69098 (SKF) discloses a rolling bearing comprising an inner ring, an outer ring, a row of rolling elements arranged between the rings, a sleeve which connects the shaft to the inner ring and which is made of a rigid synthetic material, an element for damping vibrations and a crinkle washer arranged axially between a radial surface of the sleeve and the damping element. The crinkle washer makes it possible to apply an axial preload force.
Such a rolling bearing device has the major drawback of comprising a large number of parts which must be manufactured and assembled. Moreover, such a device is not sufficiently compact in the axial dimension.